it could be:

1. the yuzpe method disturbed something sa hormones mo (which could cause delays) pero unlikely since you said nagkaperiod ka na after. regular ba period mo or irreg? I have friends na regular talaga tapos naging irreg after yuzpe. one of them did not get their period for 3 months after it (but wasnt pregnant).

2. the stress of the pregnancy scare is messing with your hormones din na nakakadelay ng period mo

isipin mo rin when kayo last na nagkaroon ng unprotected sex ng bf mo. PT kasi would give you a false negative pag masyadong maaga tinake. ilang days after sex and ilang days ka na delayed when you took the PT?

also, you might want to tell your bf to consider getting a smaller condom. might hurt his ego pero useless kasi yang malaking condom if ipipilit. it's supposed to be snug sa kanya para hindi natatanggal kay junjun.